Quick facts:

Population growth accelerated from the start of the industrial revolution, as a result of lower mortality. Fewer deaths, particularly of children, meant that more grew up to have children of their own. After WWII, the benefits of immunisation, clean water and sanitation, and antibiotics were made available in developing countries. As a result, their populations started to grow very rapidly.

In 1800, the world population was around 1 Billion. In 2016 it is around 7.5 billion.

We are adding over 80 million people to the planet annually – 1 Billion every 12 years.

Growth is not slowing – it has been roughly linear for 4 decades. (The ‘growth rate’ halved because the population doubled, not because we are adding fewer people.)

We are not past ‘peak child’ – births are increasing. (They did fall a little during the 1990s, but have risen again to a new high.)

Fertility rates are not dropping as fast as the UN’s medium projection assumes. This means that, each time the projection is revised, it increases.

No country is at risk of population collapse through a ‘birth dearth’. Not even Japan. Low fertility can cause a population decline that is gentle and manageable, and brings many benefits including more equitable access to resources and a healthier environment.

A stable population requires that births roughly match deaths. If people are going to live long and healthy lives, we must have fewer births to balance that improvement. This shift, from high birth rate with high death rate to low birth rate and low death rate, is referred to as the “demographic transition”. It is the central feature of modernisation of societies, which both reflects and enables a higher quality of life.

If a society (or the world) does not complete the transition, by achieving lower birth rates to match their lower death rates, then population pressure will cause impoverishment and instability until the death rate rises again to match the birth rate. (This is sometimes referred to as the “Malthusian check” – or the “four horsemen of the apocalypse” – pestilence, war, famine and death.)

It has been estimated that feeding 9 billion people by mid-century will require between 70% and 100% more grain to be produced than was produced in 2010. This would require faster yield improvement than in the past, even while land and water resources are more restricted.

Whether the peak human population is below 10 billion or over 12 billion will make a big difference to whether they can be adequately fed without further damaging the environment. Currently, we are heading for well over 12 billion.

About 40% of pregnancies are unintended. Over 200 million married women want to avoid pregnancy but aren’t using effective contraception. (Unmarried women and adolescents are not counted in the UN surveys. That would be like admitting they have sex! Yet a large share of the 50 million abortions per year are to single young women denied information and access to contraception.)

Through the 1970s and ’80s, voluntary family planning programs were very effective in reducing birth rates fast, regardless of extreme poverty and low education levels, and without forced ‘population control’. Catholic, Islamic, Buddhist and Hindu countries have had successful programs. Examples are South Korea, Thailand, Costa Rica, Sri Lanka, Bangladesh, Iran, Tunisia and the Maldives.

No such national program exists today. Family planning now gets only around 0.4% of international aid. The development industry either insists that population growth is not relevant to development, or that it is economic development in Africa, girls’ education and infant mortality rates that determine family size decisions, not family planning programs.

Since international support for family planning fell in the mid-1990s, the fertility rate globally stopped going down. In some countries, it increased again. This is despite strong progress on economic development in Africa, girls’ education and infant mortality rates.

Each dollar spent on family planning saves between $2 and $6 on other development interventions. The same dollar avoids more greenhouse gas emissions than a dollar spent on any renewable energy option.